Which process causes sorted sediment deposition on an alluvial fan during sheet flooding events?

💡 Explanation

When overland flow decelerates across an alluvial fan, flow competence decreases because sediment carrying capacity reduces as slope declines radially, leading to deposition of coarser material upstream and finer material further downslope. Therefore decreasing flow competence results, rather than incision, stabilization or weathering which involve different factors.

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